The small Sanjiang plain is one of the most important commodity grain production bases and the largest fresh water wetland in China. Due to the rapid expansion of agricultural activities in the past 30 years, the contradiction between economic development and the loss of ecosystem services has become an issue of increasing concern in the area. In this study, we analysed land use changes and the loss of ecosystem services value caused by these changes. We found that cropland sprawl was predominant and occurred in forest, wetland, and grassland areas in the small Sanjiang plain from 1980 to 2010. Using a model to evaluate ecosystem services value, we calculated that the decreased values of ecosystem services were 169.88 × 108 Yuan from 1980 to 2000 and 120.00 × 108 Yuan from 2000 to 2010. All of the ecosystem services were diminished from 1980 to 2010 except for food production. Therefore, the loss of ecosystem services value should be considered by the policymakers of land use and development.
Natural ecosystem services are those products and functions that contribute to humankind and other living organisms’ survival while also improving the quality of human life [
Quantitative assessment of the effects of land use changes on the value of ecosystem services is one of the research focuses of sustainable development in science [
The small Sanjiang plain is one of the most important commodity grain production bases in China. Agriculture is the leading industry in the region, and its major functions are food production and the provision of jobs and income for the local rural population [
The main goals of this study are to assess land use changes in the small Sanjiang plain from 1980 to 2010 and to evaluate the effects of these changes regarding ecosystem services. We used the value of ecosystem services to estimate the effects of regional land use changes associated with agricultural development that has occurred over the past 30 years (1980–2010).
The small Sanjiang plain (46°20′40′′
Location of the study area in Heilongjiang Province, northeast China.
In this study, three Landsat TM images from the years 1980, 2000, and 2010 were selected as the data source for land use. The pretreatment was shown in these images, which contained unified projection system and geometric correction (the error is not more than half a pixel) [
Due to a desire for more benefits and a lack of knowledge of ecosystem services value, humans have globally developed many natural ecosystems into cropland and building land in the past, resulting in altered and destroyed functions of ecosystem services and the reduced provision of ecosystem goods and services to society [
Several methods were used to estimate the value of ecosystem services, such as the simulated market approach [
In the present study, we used the benefit transfer method to estimate ESV in the Sanjiang plain based on the result of [
Ecosystem services value per unit area for different land use in China [
Ecosystem services | Cropland | Forest | Grassland | Wetland |
---|---|---|---|---|
Gas regulation | 23.35 | 1940.11 | 673.65 | 1082.33 |
Climate regulation | 435.63 | 1827.84 | 700.60 | 6085.31 |
Hydrology adjustment | 345.81 | 1836.82 | 682.63 | 6035.90 |
Erosion control | 660.18 | 1805.38 | 1005.98 | 893.71 |
Waste treatment | 624.25 | 772.45 | 592.81 | 6467.04 |
Biodiversity | 458.08 | 2025.44 | 839.82 | 1657.18 |
Food | 449.10 | 148.20 | 193.11 | 161.68 |
Raw materials | 175.15 | 1338.32 | 161.68 | 107.78 |
Entertainment | 76.35 | 934.13 | 390.72 | 2106.28 |
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Total value | 3247.90 | 12628.69 | 5241.00 | 24597.21 |
Finally, to analyse the impact of land use changes on the value of ecosystem services in two periods (1980–2000, 2000–2010), we calculated the change rate of ecosystem services value yearly. The change rate can be calculated with the formula
Land use changes in different periods and a spatial illustration were calculated by GIS and Office Excel (Figure
Land use changes from 1980 to 2010 in the small Sanjiang plain.
Land use | Area ( |
Land use change (%) | ||||
---|---|---|---|---|---|---|
1980 | 2000 | 2010 | 1980–2000 | 2000–2010 | 1980–2010 | |
Cropland | 262.19 | 346.62 | 434.82 | 32.20 | 25.45 | 65.84 |
Forest | 222.57 | 215.18 | 182.83 | −3.32 | −15.03 | −17.85 |
Grassland | 24.62 | 23.12 | 2.09 | −6.12 | −90.96 | −91.51 |
Wetland | 171.74 | 95.63 | 56.29 | −44.31 | −41.14 | −67.22 |
Building land | 11.68 | 12.42 | 16.98 | 6.30 | 36.71 | 45.32 |
Wasteland | 0.30 | 0.14 | 0.10 | −53.17 | −29.00 | −66.75 |
Land use changes over time in the small Sanjiang plain.
The increased area of cropland was the largest, measuring at
The trend of wetland changes was the opposite to that of cropland, with its decreased area being the largest (Figure
The rate of change of grassland was the largest, with a decreased rate of approximately 92% from 1980 to 2010 (Table
In this study, ecosystem services include gas regulation, climate regulation, hydrology adjustment, erosion control, waste treatment, biodiversity, food, raw materials, and entertainment (Table
ESV change from 1980 to 2010 in the small Sanjiang plain.
ESV ( |
ESV change ( |
||||||||
---|---|---|---|---|---|---|---|---|---|
1980 | 2000 | 2010 | 1980–2000 | 2000–2010 | 1980–2010 | ||||
Cropland | 85.16 | 112.58 | 141.23 | 27.42 | 28.65 | 56.07 | |||
Forest | 281.07 | 271.75 | 230.89 | −9.32 | −40.86 | −50.18 | |||
Grassland | 12.91 | 12.12 | 1.10 | −0.79 | −11.02 | −11.81 | |||
Wetland | 422.43 | 235.24 | 138.47 | −187.19 | −96.77 | −283.96 | |||
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Total ESV | 801.57 | 631.69 | 511.69 | −169.88 | −120.00 | −289.88 |
Single ecosystem service value change from 1980 to 2010.
Ecosystem services | Change ( |
||
---|---|---|---|
1980–2000 | 2000–2010 | 1980–2010 | |
Gas regulation | −9.57 | −11.75 | −21.32 |
Climate regulation | −44.09 | −27.48 | −71.58 |
Hydrology adjustment | −44.48 | −28.07 | −72.55 |
Erosion control | −2.71 | −5.65 | −8.36 |
Waste treatment | −44.61 | −23.68 | −68.29 |
Biodiversity | −10.37 | −10.80 | −21.17 |
Food | 2.42 | 2.44 | 4.86 |
Raw materials | −0.35 | −3.55 | −3.90 |
Entertainment | −16.13 | −11.46 | −27.59 |
Table
Looking at Figure
Several factors caused these decreasing trends. On the one hand, the decreased area of forest and wetland approximately equalled the increased area of cropland and building land, and yet their ecosystem services values were higher, resulting in the ecosystem services value being decreased. On the other hand, in our study, we cannot quantitatively estimate the ecosystem services value of building land, but its area increased. Furthermore, we find that food output of cropland in Table
Because of rapid population growth, the government is currently facing an enormous challenge of securing an adequate food supply in China [
The loss of wetland and forest was the most important change in the past 30 years. Because of current climate change scenarios such as an increased frequency of storms and floods [
The environmental problems of land use changes are slowly beginning to be considered in the decision-making process regarding land use. For instance, one of the goals of the water conservancy development plan of the Sanjiang plain (2005–2030) was to protect the natural ecological environment and return cropland to wetland and forest. This plan noted that the natural ecosystem that provides goods and services, such as hydrology adjustment, habitat support, and soil fertility, was very important for social sustainable development. However, although the importance of ecosystem services has been acknowledged, the value of ecosystem services has thus far not been considered for any development plans. Therefore, the present study can provide the positive influence and theoretical basis for protecting the natural ecological environment, in which the contradiction is evident between sustainable ecosystem services and land exploitation.
Due to ever-increasing agricultural expansion worldwide (especially in China), land use changes may seem increasingly economically profitable. However, when land use changes deplete the ecosystem’s capacities to deliver ecosystem services, long-term losses may exceed short-term gains. Land use and policy making should aim at balancing society’s needs and preferences, while considering ecosystem service losses as, in the long-run, it will be beneficial for all of us if natural ecosystems are preserved and used adequately.
The authors of the paper do not have a direct financial relation with the commercial identity mentioned in this paper that might lead to a conflict of interests.
This study was supported by the Special Funds for Public Welfare Projects of the Ministry of Water Resources of China (no. 201101022), the National Natural Science Foundation of China (no. 51109056), the Program for Distinguished Talents in Hohai University and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).